The present invention relates to a motor for use with, for example, a valve timing adjusting device that adjusts the valve timing in an internal combustion engine.
Japanese Laid-Open Patent Publication No. 2008-160964 describes an example of such a conventional motor that includes a motor body, a pivot shaft, a core, and an input cam (driven rotary body). The motor body includes a housing and an output shaft projecting from the housing. The pivot shaft is arranged in the output shaft orthogonal to a rotation axis of the output shaft. The core is pivotally supported by the pivot shaft and coaxially rotated with the output shaft. The input cam is annular and surrounds an outer circumference of the core. The input cam rotates integrally with the core. The input cam forms a portion of a speed reduction mechanism of the valve timing adjusting device. The speed reduction mechanism is coupled to an engine valve camshaft. Thus, rotation of the output shaft of the motor body is transmitted from the core to the input cam of the speed reduction mechanism. The rotation is decelerated by the speed reduction mechanism and transmitted to the engine valve camshaft.
A motor such as that described above is installed near an engine. Thus, the motor may be affected by engine vibration. This, for example, may incline and misalign the output shaft of the motor body and the input cam. In this regard, in the above motor, the core and the input cam pivot about the pivot shaft relative to the output shaft of the motor body. This allows the transmission of rotation even when the input cam is not coaxial to the output shaft.
Due to limitations in the available space, the above motor needs to be reduced in size in the axial direction (axial direction of the output shaft). However, the core is separated from the housing by a predetermined distance to ensure that a pivot angle is provided for the core. This increases the size of the motor in the axial direction. In this regard, there is room for improvement.